Method of forming stitches



D. BELCHER METHOD 0F FORMING STITCHES `July 13, 192e.

5 Sheets-Sheet l Filed Jan. 29. 1921 D. BELCHE'R METHOD OF' FORMING STITCHES Flled Jan 29 1921 July 13 1926.

July 13,1926. I

D. BELCHER METHOD oF FORMING sTIToHEs Fileduan. 29. 1921 `5 Sheets-Sheet 5 July 13 1926.

D. BELCHER METHOD 0F FORMING STITCHES Filed Jan. 29, 1921 5 Sheets-Sheet 4 D. BELCHER METHOD FORMING STITCHHS July 13, 1926. I 1,592,433

FuedJmzs. 1921 srsheets-sheet s Patented `luly 13, 1926.

`UNITED sTATi-:s

PATENT oFFlcE. p

DANIEL BELOHER, F ST. LOUIS, MISSOURI, ASSIGNOR T0 BEMIS BRO. BAG CO., OF

` ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

METHOD OF FOBMING STITCHES. y

Application led January 29, 1921. Serial No. 440,927.

u This invention relates to improvements in the method-of forming stitches and has for its primary objectthe forming Aof a.

mittent tension and slack take-ups are im-` parted to the threads making a smooth stitch which lies close to the'fabric in the finished article. l

In thedrawings:

Fig. 1 isa front elevation of a portion of a sewing machine showing my improvements thereon.

Fig. 2 is a rear elevation of the same.

' Fig. 3 is a top plan view.

Fig. 4 is a front end elevation.

Fig 5 is a top plan view of the' looper thread take-up cam.

Fig. 6 is a side elevatlon ofthe same.

Fig. 7 is a top'plan view of the pan teusion employedon the needle bar with portions thereof removed'.

Fig. 8 is a vertical sectional view of ythe needle thread lock.

Fig; 9 is an end view of the stud on which the needle thread lock is located.

Fig. 10 is a face view of the stationary cam made use of in the needle thread lock.

Fig. 11 is a face view of the movable cam made use of.

i. Fig. 12 is a vertical sectional View of the rocking mechanism for operating the looper.

Figs. 13, 14, 15, 16, 17- and 18 are diagrammatic views showing the operation of the looper thread take-up cam.

Fig. 19 is a plan view of the looper side ot' the stitch with a portion of the needle thread broken away and in section.

Fig. 20 is a vertical sectional view through the fabric showing the position of the needle and looper threads.

ln carrying out my method I employ a machine head having ay base secured to this hasel is the arm 26. vThearm 26 has the bearing 27 formed integral therewith and through this bearing extends the shaft .28. The hase 25 is provided at its forward end with an integral upward projection .29 inwhich one end of the shaft 28 has bearing. Qn the .other end of the shaftl 28 is mounted a sheave wheel y30, and between the sheave wheel 30 and arm 26 is located an eccentric 31. This eccentric may be formed integral with the wheel 30, it may be `made separate and mounted on the shaft 28 or it may be formed integral with the shaft without departing from the spirit or operation of my invention. Secured around the eccentric 31 is the eccentric strap 32, which has secured to and projectin from it a connecting rod 33, the free en of the rod 33 being secured to the socket 34.. `This socket has formed on its upper end the bearing 35, which is secured to the ball joint 36. This ball joint being, in turn, secured to the projection 37 formed integral with the'needle bar lever 38. The needle bar lever is pivotally secured to the arm 26 at the point indicated by the numeral 39. The end 40 of the needle bar lever is connected to the links 41, which in turn are secured to the lug 42, which lug is firmly secured to the needle bar 43. Formed integral with the arm 26 are bearings 44 in which the needle bar operates. The needle bar is provided at its lower end with screw threads over which the nut 46 is adapted to be' secured. This screw threaded portion is split and tapered, f`

as illustrated in Fig. 1, so that the tightening of the nut 46 will securely hold the needle 47 in place. The end 48 of the needle bar lever 38 is provided with a stud 49 to which is secured the bearing 50, and to this bearing is secured one end of the con-- necting rod 51, its opposite end being secured to a similar bearing 52, which is secured` to the pivot or stud 53, this stud being secured to thel looper 54. Formed integral wit-h the arm 26 is a projection 55 through which extends a screw threaded rod or bar 57, and on this bar are loosely mounted the pan tensions 57'l and 58,--the tension 57 bein on these devices is regulated by means of a thumb nut 59 and coll spring 60. Extending vthrough the projection 55 is a bar 61,

for the needle thread and the ten- 'sion 58 or the looper thread. The tension `This opening is square and is desi circularopening 85.

for the needle andy looper thread to their respective tensions. Secured to the needle bar lever 38 is a biurcated arm 62, which has seated in its bifurcation the arm 63 of the movable cammemberl 64. This cam member is provided with inclined faces 65, which contact with the inclined faces 66 of the stationary cam member 67. The movable cam member l is provided with a circular opening 68, which is adapted to it over the cylindrical portion 69 of the stud 70. This Studis secured in a bracket 71, which is attached to the arm 26. The stationary cam 67 is provided with a central opening 72. ed to fit overl the square portion 73 of t e stud 70. The stud 70 is secured in the bracket/l 71 by means of the nut 74 and the screw 75,1.

My purpose in thusl securing the stud is that the nut 74 will prevent longitudinal movement of the stud, while the screw 75 willl prevent any turning. This turning of the stud 70 would cause a variation in the de# grec of tightness between thepans 7 6and 77, as this degree of tightness is regulated entirely by turning the stud-within the bracket 71. This turning of the stud also moves with it the stationary cam member of the thread locking device, this can be readily seen from Fig. 3. If the stud were turned so that the stationary cam member would be revolved toward the needle bar or counter-clockwise, the oscillation of the movable member would bind the pans 76 and 77 more lightly than if the stud were revolved clockwise. This binding of the pans 76 and 77 and their consequent action .on the needle thread 78 is occasioned by the bifurcated bar 62 being moved up and down by the needle bar lever. This movement will in turn be communicated to the movable cam 65 and will force the stationary cam over toward the arm 26 and clamp the thread securely between the two pans. Secured' to the arm 26 is a guide 79. The purpose of this is to assist in guiding the thread'78 from the pan tension 57a to the pans 76 and 77. Secured to the needlebar lever is a loop 80. The purpose of this loop is. to assist in pulling oli' suflicent thread for the next stitch and also assistas a pull-up for the needle thread while the stitch is being formed. Near the upper end of the needle bar 43 is placed a loop 81 through which the needle thread 78 passes. This needle thread after being passed through the loop 81 is passed through the pan tension 82. This tension is secured to the needle bar 43, and the stud 83 on which the pans 84 are secured is provided with a This opening has a.

' 'slot 86 extending to the outer surface of the a guide for the needle thread and holds it at all times between the discs of the pan tension. The lower end of the needle thread 78 is passed through the eye of the needle 47. Secured to the upperportion of the arm 26 and extending on both sides of the needle bar 43 is a vertically adjustable U- shaped member 87 having its closed. portion .88 up-turned. This member regulates the starting point of the pull up and the amount. This adjustment is accomplished by loosening the set screw 136 and raising or lowering the post 137. The loop 81 is designed to ass downward between the two parallel horizontal arms 89 of the U-shaped member 87, carrying the needle thread with it and exerting an additional pull on the thread after the same has been locked by the needle thread lock. This operation will be explained in detail later.

On the end of the shaftV 28, which projects through the bearing 29, is secured a disc 90. This disc is provided with a slot 91 in i its opposite end being secured in the arml 94 of the rocking frame 95. This rocking fram-e is provided on its lower end with bearings 96 through whieh a shaft 97 extends, the ends of the shaft 97 being mounted in bearings 98 formed 'integral with the base 25. The upper portion of the rocking frame is provided with bearings 99 in which a shaft 100 is secured and mounted on the shaft 100 is an arm 101 to which is secured the toothed feeder 102. As will be noted from Fig. 4 the link 93 is eccentrically mounted in the disc This will impart a rocking motion to the fra1ne95. This rocking motion being 1n turn converted into a reciprocating motion for the feeder 102. The slot 90 is T shaped in cross section so as to prevent the head of the bolt 92 from coming out. The head of the bolt 492 is provided 'with screw threads, which receive the threaded portion of the screw 103. This is forthe purpose of varying the eccentricity of the link 93. This varying of eccentricity has direct bearing on the rate of feed of the fabric being sewed and consequently on the length of the stitch. Formed integral with the base 25 are vertical projecting lugs 104 and 105. These lugs are provided with a bore in which the shaft 106 is located. The shaft 106 projects through the lug 105 and has secured to its projecting end the U-shaped casting 107. This Uvshaped casting is provided` onl its opposite end with a lug, which has bearing in the projection 29. The U-shaped casting 107 is also provided with a lug 108, which receives the screw 109, this screw acting as a pivot for the looper 54. Secured on the shaft 106 and located between the lugs104 and 105 is a bifurcated member 110,*its bifurcation straddling the cam 111, which is mounted on one arm of the thread guide 113 resting onthe head o'f the .-screw andjollowinor it up and down. This adjustment is for tliepurpose of regulating the amount of slack taken up and also ythe time at Iwhich the looper thread contacts with the looper thread take up cam. This thread guide is provided at its olpen endv with openings through which the voo per thread 114 passes. This thread guide 1s for the purpose of directing the thread over the looper thread take up cam 115,l which is mounted on the shaft 28 and rotates therewith. This looper thread cam lis provided with a groove 116into which the thread remover 117 extends. This thread remover is also secured to the projection 112, Extending above the thread remover 117 is a hook 118, the purpose of which is to retain the thread during a certain portion of the movement of the cam 115. The cam 115 is provided with the faces 119, 120, 121, 121", 122 and 123. The purposes of these faces will be explained in detail'later. 'Thevprojections or lugs 29 and V105 are providedon their upper ends with the plane surfaces 124, and in these surfaces are formed screw threaded openings for the purposeof securing a plate thereto (not shown in the drawings), which plate acts as a rest for the work.

The base 25 is also provided with a projecting lug 125 to which a cover (not shown) is hingedly connected. This cover is for the purpose. of covering the mechanism, which operates the rocker frame 95.v Mounted in the arm 26 is a presser foot bar 126 to which the presser foot 127 is secured and secured to the presser foot bar126 is a projecting 'lug 128 on which one end of the presser spring 129 restsf' yIts other end being secured to the projecting lug 55. The desired pressure is imparted to the spring 129 by means of the adjustinglscrew 130. The presser'foot 127 and bar 126 are raised by means of the eccentric lever 131. purpose of making the desired adjustment of the various tensions and for threading the looper as the machine can then be easily turned by hand So that the various parts assume the necessary position. The eccentric `lever 131`contacts with the rejecting st'ud 132, v.which -is connected to t e presser foot.

bar 126. In order tokeep the bar'126 and presser foot from turning I make use of the the cam 115.

This lifting is for the short sliding, shaft 133, which isconnected to the bar 126 by means of the stud 134. This holds the presser foot in alignment with the `feed plate` 102 and prevents its turning when employing vthe eccentric lever 131. .v

Secured to the-base 25 is a guide -135,`which is for the purpose of guiding the looper thread from the pan tension to A,the U-shaped thread guide 113.

The operation of my device is as follows:

In threading the machine the needle -thread 78 is first passed through the openin -formed in the bar 61. This opening being on the front side of the machine. The thread is then passed underneath the bar 57 and between the pans 57'L of the pan tension, it is then passed' under the thread guide 79. From there it is passed betwcen,the pans 76 and 77 ofl the thread lock, then through the loop 80, vthen upward through the loop or thread guide 81, which is attached to the upper end of the needle bar, and then downward andl inserted into the pan tension carried by the needle bar. This is done by slidin one of the pans backward toward the need e bar and inserting the thread into the slot 86 and then pulling it forward until it passes into the opening 85 formed in the stud 83. through the eye in the needle 47. The looper thread 114 is passed through the open ing in the bar 61 o n the back Side ofthe machine, thence between the pans of the pan tension 58, then downward and through the thread guide 135. It is then passed through the openings formed in the U-shaped guide 113. This causes the thread to pass over spring 129 is regulated, as is the tension on 1s ready for operation. The work is inserted beneath the front of the resser foot and then drawn. beneath it by t e operation of the machine. Assuming that the needle bar is raised to its highest point, as illustrated in the drawings, the sheave wheel 30 is placed in operation by means of a belt which leads from an suitable source of energy, such as a line s aft, motor, or the like. Th`e needle bar being operated by -the needle bar lever 38 now commences to descend, carrying with it the needle thread 78. ThisV o eration commences to lock the thread 78 1n the thread lock', while the loop 80 carries downward with it the slack, which is formed between the thread lock and the"loop 81; This slack' continues to form until the loop 81 is about to pass between the horizontal portions of the thread take-up or U-shaped member 87. movement of the needle bar carries this loop 81 downward still farther and exerts` The threadis. then passed The thread is then 'passed `through the looper 54; the tension on the ma r no i

The continued downward e a dowhward pull on the thread. This down- `ward pull draws up the'.previously formed stitch, and also draws a certain amount of slack for the next operation or next stitch. Just as vthe needle is ready to descend the looper is in the position shown in Fig. 1

and the looper take-up cam in the position shown in Figs. 3 and 14. As the needle commences to descend, the looper thread is carried upward by the face 119 of the looper cam, as illustrated in Fig. 14, and comes in l0 contact with the thread remover 117 and 1,5 the hook 118, where it remains until theface 121 jcommences to pass the hook 118 when the thread is released from the hook and allowed to drop on to the face 121. It is lduring this time that the needle thread is pulled up taut by the needle thread slack take-up, which is composed of the. U-shaped member 87 and the loop 81. This allows the needle thread to be firmly seated or drawn up tightly. At this inst-ant the looper is drawn backward to its farthest. ex-

tent,-tlie looper then commences to travel forward and at the same. time the projection 121a of the cam v115 catches the' thread and pulls it upward. This seats the looper thread in the vprevious stitch. This pulling up continues until the thread remover 117 has carried the thread upward so that it rides on the face 122 when the thread again moves forward or is released sulliciently to engage the hook 118, as in Fig. 17. The thread is now released from the hook 118 and rides on the face 123, which when pull is exerted oirthe thread allows it to ride downward and C11-op against the face 119 when the operation is repeated.l During this movement as the needle travels upward, a loop of thread is left below the fabric and to the rear of the needle, which loop the looper enters due to its being rocked to the backside of the needle by the cam 111 and the bifurcated member 110. This, as previously pointed out, oscillates the U-shaped member 107 to which the looper 54 is pivoted. The connecting rod 51 being attached to the lower end of the needle bar lever 38 is pushed forward during the operation of raising the needle bar. As the needle commences to descend, the looper is oscillated forward so that it is brought to the front of the needle and travels backward releasing the loop already formed with the looper thread secured therein, through which loop theneedle passes. After the needle is again raised these loops are carried forward by the feed plate- 102 and as the needle continues to descend the loop of needle thread ofthe previous stitch is drawn up tight.

The saving of thread is illustrated in the following example, although any of several thread combinations may be used:

In this instance, the thread used is 5 ply for the needle thread and 3 ply for the looper thread and the basis of measurement of thread being a one ply thread so that one foot of needle thread will be equivalent to 5 feet of one ply thread, and one foot of looper thread equivalent to 3 feet of one ply thread. In the old stitch made by machines as used at present for bag sewing lthere are approximately 3.5 of 5 ply thread used in every foot, or 10.5 feet of one ply` l thread. This makes a total of 18 feet of one ply thread used by' my device in sewing one foot of fabric, as against 22 feetof one ply thread in the old device. This means a saving of 4 feet of one ply thread in every foot of sewing, which will run into a considerable amount in the course of a dafy when it is figured that each machine turns out severalthousand completed articles a day. As will be noted from Figs. 19 and 20, one strand of the looper thread passes entirely around the loo of needle thread extending below'the fabric, one strand passes through the loop alid-one strand is bent around one of the threads of the needle thread. This makes a total of 3 strands of looperthread between adjacent loops of needle thread;

and as shown in Fig. 20, by means of my improvement a portion of the looper thread.

is partiall or wholly imbedded in the fabric depen ing entirely upon the coalseness of weave and the material out of which the bag is formed, the thread used in sewing `cementbags and the like being not as deep-v ly imbedded as the thread used in sewing? gunny sacks, the latter being made of softer and coarser material.

During the operation of my device the pan tension carried by the needle bar prevents any slack forming between it and the needle. Were this tension not present, a loop of thread would be left hanging below the needle point when the needle starts or. its downward travel, and it'has been found by actual experience that the needle in descending will pass through this loop of slack and cause -a n additional loop, which .the loo er will cut when entering the loop below t e fabric andI thus makev it im ossible to make a continuous stitch, t ere being a number of short sewed portions,

. causes the rejection of the work and consequently a loss of time and money in ripping the work and resewing it. f

It will be observed from the foregoing description that the thread lock, the loop on the needle bar lever and the loop on the needle bar, the tension on the needle bar, the U-shaped member carried by the. arm 26 and thel looper thread take up cam co-act and are necessary in forming the stitch illustrated and described. The thread' lock operates' intermittently to increase the tension on the needle thread, but does not lock the thread entirely against movement. This is necessary to seat the loop of needle thread firmly around the looper thread in the formed stitch. Were this intermittent tension not present the needle thread could not be drawn up tightly by means of the U-Shaped. member and the loop 81. The loop 8O carried by the needle bar lever also serves the purpose of retaining the thread within 'the thread lock. Were this loop not present the tendency of the loop 81 would be to cause the thread to jump out of the thread lock due to the rapid up 'and down movement of the needle bar. The loop in the upper end of the needle bar and the U-shaped member carried by the arm 26 act as previously pointed out in drawing up the needle thread. This action taking place when the needle has almost completed its downward stroke and while the needle thread is under the additional tension imparted to it by means of the intermittent thread lock, thus taking up the slack while the needle is descending. The thread tension carried by the needle bar also performs the function of a thread support for holding the thread and preventing it from forming a double l-oop on both sides of the needle. In addition to the functions of the special form of looper thread takeup cam, besides forming the slack and re leasing it, has another drawing-up movement, which acts as a slack take-up for the looper thread and has a tendency to cause it to lie closely to the fabric, instead of being looped between the stitches of needle thread, and it also holds the looper thread under this tension'long enough to allow the needle thread to be drawn `in and then it is released when the goods are beingfed forward. Were this not done the looper thread would be broken.

While I have shown my attachments applied to a particular type of sewing xnachine, it is obvious that with slight modifi-4 cation they can be adapted to any sewing machine that takes thread from large'spools .stitches comprising the employment of a supply of needle thread and a supply of smaller looper thread, applying to said threads near the source of supply a constant and initial tension, forming a loop in the needle thread below the fabric, passing a loop of looper thread through the needle thread loop, passing a loo'p of needle thread through the loop :of looper thread, applying intermittent tension to the needle thread and simultaneously exerting an upward pull on the branch of .the needle thread loop adjacent the interdrawing off a sufficient amount of thread to v form a stitch,'and applying intermittent ad ditional tension and pulling up movement to the needle thread between the source of supply and the needle, and pulling up and slack-v ing movements to the loo er thread during the formation of the stitc i.

3. The hereindescribedmethod of forming stitches comprising the employment of a supply of needle thread and a supply of smaller looper thread, applying to said threads .near the source of supply a constant and initial tension, forming a loo`p` inthe needle thread below the `fabric, assing a loop of looper thread through the needle thread loop and momentaril arresting the feed of the looper thread an taking up the slack therein while being passed through said loop, passing a loop o needle thread through the loop of looper thread, simultaneously applylng intermittent tension to and exerting an'upward pull on the branch of the needle thread loop adjacent the intermittent tension, thereby drawing up and seating the first mentioned loop of needlek thread against the fabric.

4. The hereindescribed method 'of forming stitches comprising the employment of a supply of needle thread and a supply of` loop o looper thread, applying intermittent tension to and exertin an upward pull on the branch of the nee le'thread loop ad'acent the intermittent tension simultaneously, thereby. drawing up `and seating the first mntioned loop of needle thread againstv the fa ric.

is being formed, passin a loop of'needle thread through the visis 5. The herein described method of forming stitches, comprising the employment of asu ply of needle thread and a supply of sma er looper thread, applying to said threadsnear the source of supply a constant and initial tension,- forming a loop in the needle thread below the fabric, passing a loop of looper thread through the needle thread loop, passin a loop of needle thread through the loop o looper thread, applyingV intermittent tension to the needle thread, and simultaneously exerting an upward pull on the branch of the needle thread adjacent the intermittent tension while the needle is l still descending and the intermittent tension still applies, thereby drawing up and seating the first mentioned loop of needle thread against the fabric so that it extends below the fabric only suliiciently to accommodate the loops of loo er thread.

6. The metho ofrforming stitches which consists in taking a suitable source ofsu ply ofneedle and looper thread, placing t e same under a constant regulated tension, drawing off more than a sutiicient amount of thread to form a stitch, and applying intermittent additional tension and pulling up movement to the needle thread between the needle and source of supply during the last period of the downward travel of the needle while a stitch is being formed.

7. The herein described method of forming stitches, comprising the employment of a supply of needle thread and a supply ofsmaller looper thread, applying to said threads near the source of supply a constant and initial tension, forming aloop in the needle thread below the fabric, passing a -1 loop of looper thread through the' needle -ag Iainst vthe fabric.

8. The herein described method of formstitches, comprising the employment of a su plyofneed e thread and a supply of ama er looper thread, applying to said .thread near the source of supply a constant and initial tension, forming a loop in the needle threadbelow the fabric, assing a Yloop oflooper thread through t e nee-'lle `thread-loop,ltaking up and forming slack in the looperthread during different timed intervals while the stitch is being formed,

passing a loop of needle thread through the' same under a constant regulated tension,r

drawing off a sufficient amount of thread to form a stitch, applying intermittent addition tension and pulling up movement to the branch of needle thread thus tensioned during a portion of the downward travel of the needle and while a stitch is being formed, and, applying a constant regulated tension to the needle thread for preventing the formation of a double loop of needle thread. `f

10. The herein described method of forming stitches comprisingthe employment of a supply of needle thread and a supply of smaller looper thread, applying to said threads near the source of Supply a constant and initial tension, forming a loop in the needle thread vbelow the fabric, passing a loop of .looper thread through the needle thread loop, passin a loop of needle thread through the loop o loo er thread, applying intermittent tension to t e needle thread and vsimultaneously exerting an upward pull on the branch of the needle thread loop thus tensioned, thereby drawing up and seating the first mentioned loop of needle thread against the fabric, so that it extends below the fabriconl sutliciently -to accommodate the loops of ooper thread, and applying a constant regulatedV tension to the needle thread to prevent the formation of a double loop of needle thread.

11. The herein described method of forming stitches com rising the employment of a supply of nee le thread and a supply of smaller looper thread, applying to said threads near the source of supply a constant and initial tension, forming a loop in the needle' thread below the fabric, passing a loop of looper thread through the needle thread loop and momentarily arresting the feed of the lower thread and taking up the slack therein while being passed thrpugh said loop, passing a loop of needle thread through the loop of looper thread applyin intermittent tension to the needle threadl an simultaneously exerting an upward pull on the intermittently tensioned ranch of the needle thread loop while said tension is apfplied, thereby drawing up and seating t first mentioned loop'of needle thread against the fabric, and applying a' second constant regulated tension to the needle thread vto prevent the formation of a double loop of needle thread. i

,i el

1 a supply of nee e thread and a supply of smal er looper thread, applying to said threads near the source of supply a` constant and initial tension, forming a loop in the needle thread below the fabric, assing a loop vof looper thread through t eneedle thread loop and momentarilarresting thefeed of the ooper threadah taking up the slack therein, while being passed through said loop, passing a loop of needle thread, through the loop lof looper'thread, applying intermittent tension to and exerting an u ward pull Lon the tensional branch of e needle threadloop during the last portion of the needle descent, thereby drawing up and seating the first mentioned loop of a l plying a constant regulated tension to the needle thread to prevent the -formation of a double loop of needle thread.

13. The'method of forming stitches which consists in takin a suitable source of su ply of needle ang looper thread, placing t e same under a yconstant regulated tension.' near the source of supply, drawing oi from` .e'ach ja suicient amount ofA thread to formv la stitch, applying intermittent additional tension to one branch ofthe needlethread and causing a retrograde movement of the tensioned branch of needle thread, whereby the `loop of needle thread is drawn up against two strands of looper thread and prevented from lying along the looper side 4of the fabric.

14. The herein described method of forming stitches comprising the employment of a source of supply of needle thread and 'of looper thread, applying to said threads near the source of supply a constant and initial tension, formin a loop in the needle thread below the fabrlc, passing a loop of looper thread through the vneedle thread loop and momentarily arresting the feed of the looper thread and 'taking up the slack therein while being paedthrough said loop, passing aloop of needle thread through the` loop of looper thread, applying intermittent tension to the branch of needle thread adjacent the source of supply causing the branchthus ensioned to travel in a retrograde direction while the needle is still descending thereby drawing up and seating the first mentioned loop' of needle thread against two strands of lggpler thread thus spreading the loop of. n efthread and preventing it from exalong the, looper thread side of the a ne. A

15. The method of forming stitches which consists in the employment of needle and looper threads, passing a loop of needle thread through the fabric to be sewed,` passing a loop of looper thread through the loop of needle thread, passing a secondloop of'needle thread through the loop of looper thread, and imparting a retrograde movement tothe needle thread through the eye of the needle, thus drawing up the first mentioned loops of needle thread tightly against -I two stran of looper thread.

In testimony whereof, I have signed my name to this specification.

p DANIEL BELCHER. 

